The 5 Whys method is an interrogative problem-solving technique that seeks to understand cause-and-effect relationships. At its core, the technique is used to identify the root cause of a problem by asking the question of why five times. This might unlock new ways to think about a problem and therefore devise a creative solution to solve it.
Understanding the 5 Whys Method
The 5 Whys method was instituted by Toyota employee Taiichi Ohno in the 1950s.
Ohno developed the technique as the basis of Toyota’s scientific approach to problem-solving.
He argued that “by repeating why five times, the nature of the problem as well as its solution becomes clear.”
In modern business, the method has expanded well beyond the automotive industry.
It is especially popular in the lean development of software, itself based on Toyota’s minimum waste and maximum value ethos in production line manufacturing.
Regardless of the industry however, the 5 Whys Method is effective at addressing recurring problems.
By their very nature, these problems recur because their root cause has not been identified.
A business with such a problem is only treating the symptoms of that problem and does not have a strategy to completely address it.
Implementing the 5 Whys Method in practice
There are several steps to undertaking the 5 Whys Method, outlined below.
1. Assemble a team
Ideally, the 5 Whys method should not be undertaken by a sole individual.
A team should instead consist of members that are experienced in dealing with the problem concerned.
Each team member should also be encouraged to share their unique insights and point of view.
2. Identify the problem
The problem must be identified and agreed upon, because it very much dictates the direction of the five questions that follow.
Wherever possible, the team must identify problems with process, and not personnel.
The scope of the problem must also adequately be described.
A problem with too broad a scope will be resource-intensive to address and may inadvertently conflict with company values or strategy.
Too narrow a scope may result in insignificant improvements that do little to prevent problem recurrence.
3. Ask why
Next, a mediator should begin the process of asking why.
Each time the question is asked, the answers should be based on facts or hard data.
They should not be based on often emotional answers that are given by team members.
The team should move through each level of the method so long as there is potential for the problem to occur.
Here, it’s important to note that some root causes may be identified in less than 5 steps. Others may require more than five.
4. Identify the solutions
Once the root cause has been determined, a list of solutions must be created to address it.
Although not expressly a part of the 5 Whys method, many businesses choose to use the 5 How strategy in solution development.
This involves taking each root cause and asking “How?” a further five times until the root solution is arrived at.
Irrespective of how solutions are formulated, the business must test them in a workplace scenario.
If they are found to be ineffective, then the 5 Whys method should be repeated from the start.
Limitations of the 5 Whys Analysis
The 5 Whys analysis is a great tool to start inquiring about the core issues of a business.
It’s extremely effective as it helps you get closer to the root cause of a problem.
However, for that to work, this analysis must turn into a real, in-depth investigation of a problem.
Indeed, often this might turn into a sterile tool, as those using it only shallowly look at the problem at hand, thus confusing a symptom for the root cause.
For instance, take the case of a manager analyzing customer complaints, making many theoretical hypotheses with the 5 Whys analysis, but by never talking with the final customers.
While the analysis might be potentially a great tool to inquire into customers’ issues, in reality, that might turn into a misleading tool if not used properly.
5 Whys Analysis Example
Take the case of a company receiving many customers’ complaints, and it wants to go to the root cause of it.
The company must understand whether the product has manufacturing defects or isn’t delivered as it should.
Take the case of a company selling electric brooms, and lately received various complaints about these products not working as they should.
So it starts to drill down with various questions:
- Why are customers complaining about the product? The product arrived on time, but it wasn’t working as expected.
- Why is the product not working as expected? As the customer opened the product and tried to make it work, it wasn’t cleaning as promised.
- Why is the product not delivering on the expectations? After running various checks, it turned out that a key filter was missing.
- Why is that filter missing? One of the manufacturing facilities had issues related to supplying some critical raw materials, among which filters seemed to be missing.
- Why are filters missing? From a further investigation, it turns out that the company was using an inventory of old filters, using old technology, as the supply of new filters was scarce.
From the analysis above, the company realizes that it has a problem with a manufacturer of filters that is not able to keep up with demand.
Thus, the company closes an exclusive agreement with the supplier, which will primarily provide these new filters to the company, thus solving the manufacturing issue.
5 Whys and Fishbone

The fishbone diagram is a great companion tool to the 5 Whys Analysis.
5 Whys and Root Cause Analysis

The 5 Whys method can also be integrated with a root cause analysis tool to make it more effective.
Key takeaways
- The 5 Whys method is the iterative discussion of a problem that follows one train of thought to a logical conclusion.
- The 5 Whys method is used to address recurring problems by identifying and then addressing the root cause to prevent future recurrence.
- The 5 Whys method is a four-step process where individuals with experience in the problem at hand come together to brainstorm potential solutions. The method is sometimes supplemented with the “5 How” root solution technique.
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- BCG Matrix
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- VRIO Framework
Additional resources: